Question

In a clinical trial $30$, patients with a certain blood disease are randomly assigned to two groups. One group is then randomly assigned the currently marketed medicine, and the other group receives the experimental medicine. Each week, patients report to the clinic where blood tests are conducted. The lab technician is unaware of the kind of medicine the patient is taking, and the patient is also unaware of which medicine he or she has been given. This design can be described as

(a) a double-blind, completely randomized experiment, with the currently marketed medicine and the experimental medicine as the two treatments.

(b) a single-blind, completely randomized experiment, with the currently marketed medicine and the experimental medicine as the two treatments.

(c) a double-blind, matched pairs design, with the currently marketed medicine and the experimental medicine forming a pair.

(d) a double-blind, block design that is not a matched pairs design, with the currently marketed medicine and the experimental medicine as the two blocks.

(e) a double-blind, randomized observational study.

Short answer

(a) Double-blind, completely randomized experiment with the currently marked medicine and the experimental medicine as the two.

Step-by-step solution

Part (a) step 1: Given Information

A double-blind study is the one in which neither the participants nor the experimenters know who is receiving a particular treatment. Which procedure is utilized to prevent bias in research results.

Part (a) step 2: Explanation

A double-blind experiment is one in which neither the subjects nor the individuals who measure know which was received, while in a single-blind experiment either the individuals who measure or the subjects know which treatment was received.

Double-blind

The patients are randomly assigned to the groups and an experiment deliberately imposes some treatment on individuals in order to observe their responses:

Completely randomized experiment

with the two types of medicine.

Part (b) step 1: Given Information

A type of clinical trial in which only the researcher doing the study which is known as treatment or intervention the participant is receiving until the trial is over. A single-blind study makes the results of the study less to be biased. Means the results are less likely to be affected by factors that are not related to the treatment or intervention being tested.

Part (b) step 2: Explanation

A single-blind, completely randomized experiment, with the currently marketed medicine and the experimental medicine as the two treatments is not the correct answer.

Part (c) step 1: Given Information

A matched pairs design is a case of a block design. It is used when the experiment has two treatment conditions; and subjects can be grouped into pairs, based on some blocking variable. So, with in each pair, subjects are randomly assigned to different treatments.

Part (c) 2: Explanation

A double-blind, matched pairs design, with the currently marketed medicine and the experimental medicine forming a pair is not correct answer.

Part (d) step 1: Given Information

Matched-pairs experimental design is used in studies with low numbers of participants and only two possible treatment conditions.

Part (d) step 2: Explanation

A double-blind, block design that is not a matched pairs design, with the currently marketed medicine and the experimental medicine as the two blocks is not the correct answer.

Part (e) step 1: Given Information

A double-blind study is one is neither the participants nor experimenters know who is receiving a particular treatment. The procedure is utilized to show in research results.

Part (e) step 2: Explanation

A double-blind, randomized observational study is the wrong answer.